Recently, a multimedia communication system which provides a multimedia service has been actively researched. The multimedia service includes a conversational service such as a video phone, a streaming service such as a Video On Demand (VOD) service, a service such as a multicast multimedia service and a broadcast multimedia service. The multimedia service may be classified into a real time multimedia service and a non real time multimedia service, and the real time multimedia service may be classified into the conversational service, an interactive service, the streaming service, etc. according to a service type. Further, the multimedia service may be classified into a unicast multimedia service, the multicast multimedia service, and the broadcast multimedia service according to the number of User Equipments (UEs) which receive the multimedia service.
In an Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, e.g., an IEEE 802.16 based Worldwide Interoperability for Microwave Access (WIMAX) standard, an IEEE 802.11e standard, e.g., an IEEE 802.11e based Wireless Fidelity Transmission Opportunity (WiFi TXOP) standard, and an Universal Mobile Telecommunications System (UMTS) standard and a Long Term Evolution (LTE) standard of the 3rd Generation Partnership Project (3GPP), a function of reserving a resource for providing a multimedia service and guaranteeing the reserved resource has been proposed.
The multimedia communication system may use the following resource reservation protocols in order to guarantee a Quality of Service (QoS) of a real time multimedia service.
In the resource reservation protocols such as a traffic specification (tspec), a request specification (rspec), and a flow specification (flowspec) included in a Resource Reservation Protocol (RSVP) as a resource reservation protocol used in an Internet Engineering Task Force (IETF), various parameters are defined, and the various parameters have a compatibility with the IEEE 802.16 standard, the IEEE 802.11e standard, the UMTS standard and the LTE standard of 3GPP.
In the IEEE 802.16 standard, the IEEE 802.11e standard, the UMTS standard and the LTE standard of 3GPP, a resource is generally reserved using a double leaky bucket parameter.
FIG. 1 schematically illustrates a process for expressing data with a variable bit rate using a double leaky bucket parameter in a multimedia communication system according to the related art.
Referring to FIG. 1, a traffic with a variable bit rate is expressed in a form of double leaky bucket using four parameters (Rg, Rp, Bp, B) included in a tspec of a RSVP. Here, Rg is a parameter denoting a guaranteed bit rate, Rp is a parameter denoting a peak bit rate, Bp is a parameter denoting a buffer size for the peak bit rate, and B is a parameter denoting a buffer size.
In FIG. 1, a guaranteed bit rate Rg 101 denotes a given average bit rate, an overflow does not occur if related bits are stored in a buffer at a related timing point even though a bit rate at the related timing point is momentarily greater than the guaranteed bit rate Rg 101. In FIG. 1, it will be assumed that a buffer size necessary for the guaranteed bit rate Rg 101 is B 103. In some cases, the buffer size B 103 corresponds to the guaranteed bit rate Rg 101, and may be expressed as a guaranteed buffer size Bg.
Further, a peak bit rate Rp 105 may be previously determined. If it is assumed that the peak bit rate Rp 105 is maintained within a period in which one data packet is transmitted, a buffer size Bp 107 for the peak bit rate Rp 105 may be determined as a maximum size for a Service Data Unit (SDU). The maximum size for the SDU may be generally expressed using a Maximum Transfer Unit (MTU).
An example of various protocols using four double leaky bucket parameters is expressed in Table 1.
TABLE 1IETFRSVP,IEEEIEEE3GPP802.11e802.16UMTS &‘tspec’(WIMAX)LTEMPEG-4 ODATMRppMin.MaximumavgBitratePCRreservedbit ratetraffic rate(4B)BpMSDU sizeMaximumMAX_AU_SIZECDVTSDU sizeRgRMax.GuaranteedAverageBitRateSCRsustainedbit ratetraffic rate(4B)BgbMaximumk*bufferSizeDBBTLatencyMaximumSDUAs expressed in Table 1, p, M, r, b corresponding to Rg, Rp, Bp, B are used in an IETF RSVP and an IEEE 802.11e tspec, Minimum reserved traffic rate, SDU size, Maximum sustained traffic rate, Maximum Latency corresponding to Rg, Rp, Bp, B are used in an IEEE 802.16 based WIMAX standard, Maximum bit rate (4B), Maximum SDU size, Guaranteed bit rate (4B), k* Maximum SDU corresponding to Rg, Rp, Bp, B are used in a 3GPP UMTS & LTE standard, avgBitrate, MAX_AU_SIZE, AverageBitRate, bufferSizeDB corresponding to Rg, Rp, Bp, B are used in a Moving Picture Expert Group (MPEG)-4 Object Descriptors (OD) standard, and PCR, CDVT, SCR, BT corresponding to Rg, Rp, Bp, B are used in an Asynchronous Transfer Mode (ATM) standard.
A detailed description of p, M, r, b used in the IETF RSVP and the IEEE 802.11e tspec, Minimum reserved traffic rate, SDU size, Maximum sustained traffic rate, Maximum Latency used in the IEEE 802.16 based WIMAX standard, Maximum bitrate (4B), Maximum SDU size, Guaranteed bitrate (4B), k*Maximum SDU used in the 3GPP UMTS & LTE standard, avgBitrate, MAX_AU_SIZE, AverageBitRate, bufferSizeDB used in the MPEG-4 OD standard, and PCR, CDVT, SCR, BT used in the ATM standard will be omitted herein.
As expressed in Table 1, it is advantageous in view of compatibility with other protocols to generate multimedia data delivery characteristics information using the double leaky bucket parameters.
Generally, a resource reservation protocol is set up in a service session establishment process for providing a multimedia service. It is assumed that the resource reservation protocol is set up while the multimedia service is performed, that is, the resource reservation protocol is set up among end points on a network which transmits data for all of multimedia contents.
However, it is impossible to reserve a resource among end points which are provided a service in an open internet environment of the related art. In a core network, a stable and wideband transmission is possible, however, a problem due to resource sharing among a plurality of UEs may occur at a closer point to end points. Specially, in a wireless communication and a mobile communication system, network environment dynamically changes due to various reasons such as movement of a UE, electronic interference, etc. For convenience in explanation, the network environment which dynamically changes will be referred to as a ‘dynamic network environment’.
FIG. 2 schematically illustrates a change of dynamic network environment in a mobile network of a communication system according to the related art.
Referring to FIG. 2, for example, the mobile network may be an IEEE 802.16 network using an IEEE 802.16 standard. In a graph in FIG. 2, a horizontal axis indicates time, and a vertical axis indicates a Signal to Interference plus Noise Ratio (SINR)(dB) measured at related time. That is, the graph in FIG. 2 indicates SINRs which have been measured during 10 minutes.
Meanwhile, in a related-art MPEG standard, a MPEG Media Transport (MMT) technology has been standardized. In the MMT technology, a function of reserving a resource for a multimedia service and guaranteeing the reserved resource, a function of generating multimedia data delivery characteristics information in dynamic network environment and transmitting/receiving the generated multimedia data delivery characteristics information, etc. have been studied.
In the MMT technology, an MMT asset unit of delivery characteristics information is provided using Asset Delivery Characteristics (ADC) information.
The MMT asset includes one or more Media Processing Units (MPUs). The MPU is packetized into one or more MMT payloads according to a size. That is, the MPU may be packetized into one MMT payload according to a Maximum Transport Unit (MTU) size, or packetized into a plurality of MMT payloads by fragmenting the MPU, or packetized into one MMT payload including a plurality of MPUs by aggregating the MPU. The MMT asset is the largest data unit to which composition information and delivery characteristics are applied.
The ADC information is information for guaranteeing a QoS of the MMT asset delivery, and denotes a medium parameter for specific transmission environment and a medium parameter for guaranteeing the QoS.
So, in the MMT system using the MMT technology, a service provider should establish a network by considering the multimedia data delivery characteristics information using the ADC information.
In the dynamic network environment, it becomes difficult to guarantee a reserved resource if a resource is reserved at a service session start timing point using a related-art protocol such as a RSVP. Due to mobile environment characteristics, a Base Station (BS) which provides a service to a UE changes if the UE moves, so there is a need for a new resource reservation process. Therefore, there is a need for guaranteeing a QoS of a multimedia service in dynamic network environment.
If the resource is reserved at the service session start timing point even though a data rate variously changes according to multimedia data delivery characteristics, a resource guaranteed according to the resource reservation may not be used. Further, it is difficult to share the non-used resource with other UEs. So, there is a need for dynamically reserving/allocating a resource according to dynamic multimedia data delivery characteristics.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.